Study of the heat and mass transfer characteristics of metal hydride beds

Abstract

Understanding of the heat and mass transfer characteristics of metal hydride beds is very important in studying the enhancement of heat and mass transfer in metal hydride beds and in designing the reactor vessels in an optimum way. Until now, only models with constant hydrogen and metal hydride physical properties have been presented. These models cannot reflect the practical cases well. In the present study, a more practical model is presented. The model not only includes the effects of the effective thermal conductivity in the hydride bed, which is severely affected by the hydrogen pressure and hydrogen-to-metal ratio, but also includes the effects of the physical properties of the metal hydride and other operating parameters. The numerical results of the TiMn 1.5 hydride bed show that the hydriding or dehydriding reaction occurs in the entire hydride bed, but the main reaction occurs in a rather narrow region, and that the enhancement of heat transfer in the metal hydride bed is very important in shortening the reaction time.